Gear-generating machine



E. R. FELLOWS. GEAR GENERATING MACHINE. APPLXCATION FILED DEC. 24, 1917..

Emma May 4,1920.

5 SHEETS-SHEET l- E. R. FELLQWS. GEAR GENERATING MACHINE. APPLICATION FILED DEC. 24,|917

mm May4,1920

5 SH EE'I'SSHEET 2.

R. FELLOWS. GEAR GENERATING MACHINE. APPLICATION FILED D5024 19H.

Pat ented May 4, 1929. I

v 5 SHEETS-SHEET 3- II II II IIIIIIHIHI III!" III I I ER FELLOWS. GEAR GENERATSNG MACHINE.

APPLICATION FILED DEC. 24 1917.

R rd 0 T w 4 r H M in MM A m VQ a s 1 N n M c, m m m If P W m M W. H mm W m I mi. e. m \kl lllfililllllllll E. R. FELLOWS GEAR GENERATING 'MAcHmE.

' APPLICATION FILED DEC. 24, 1917.

PE /seated May 4,1920;

5 SHEETS-SHEET 5.

has

MW M N LIIJPI v kowmwfikowin q WMNE involute tooth by metal cutting 'EDWIN a. FELLOWS, or srnmer am, VERMONT.

GEAR-GENERATING MAc'HntE.

Application filed December 24,1917. Serial No. 208,547.

To all w/wm it may concern.

Be it known that I, EDWIN R. FELLOWS,

a citizen of the United States, residing at.v

Springfield, in the county of Windsor and State of Vermont, have invented new and useful Improvements in Gear-Generating Machines, ofwhich the following is a specification.

The present invention relates to the art of generating gear elements, particularly those of the spur gear type, and'has for its object, generally,to provide means by which the teeth of gears may be accurately cut and their face curves correctly generated with the use of a rotating cutting tool and, specifically, to finish previously cut and hardened gears by grinding, with accurate generation of the tooth curves at the same time. The specific embodiment of the invention chosen 'for illustration herein is a grinding machine adapted to finish -steel gears which have been rough cut and hardened and are therefore too hard to be cut tools, and therotating' tool of such machine is a the principles for whic I claim protection are not limited by the nature of the tool used.

roducm 'a relative movement P s gear isrolled in mesh witha complemental gear or rack, between the work piece and a 'grinding wheel which has aface corresponding to the face of the complemental or conjugate tooth, the wheel being meanwhile driven rotatively at high. speed with such face in contact with the gtace of a tooth on the work piece, whereby the latter is cut away to the desired form. This prining cutters, closure ci a in connection with'the' discurves by the action, of a gllllfllllg.-Wl18t3l,glih8 working face of which is a plane surface and corresponds to the tooth 'ifacenoif a'rack, called in practice the base rackPwith-which the gear is designed ta'mesh; I

Tha -main object of the present invention is -to g'furnish a machine operating on the principle' above indicated which shall be capable of producing finished gears having Specification of Letters Patent.

'ing from one another rinding wheel; but

The principle on which the machine is I based is that of'generating the tooth face curves by essentially like that which occurs when a intersected by line 9-9 of detail taken on line machine designed to generate Patented May 4, 192.0.

any size, any pitch, and any degree of tooth angle, within proper limits; and to provide in connection therewith such means and ad justments for this purpose, that the same machine may be fitted, in the briefest-possi 'ble' time and without substitution ofparts other than the change of a small number of changeable gears, to turn out ears djfier' in any 0 .thesechar acteristica. Further objects, contributory to that above stated, appear in the following description of a concrete machineflembodying theprinciples ofthe'invent'ion and illustrating an operative means for. carrying. such principles into effect. The'invention consists in the principlesunderlying the means embodied in said machine, as well as in the specific mechanisms so illustrated. Said machine is presented. for the purpose of illustration and explanationof such principles without intent to limit the scopeof the protection whichl'claimotherwise than as appears from the appended claims.

Figure 1 is a front elevation, with arts broken. away and shown in section, '0 the particular machine referred to. t

F ig. .2 is a right hand end elevation of the machine.

3 is aleft hand endelevation.

Fig. 4 isa cro's'sscction 'on line 44 of F Fig. 5 is a cross section on linen-5 of i l. V

ig. 6 is a plan view of the machine. ig. is a of Fig. 1.

Fig. 8 is a horizontal Of Fig.1, inn gear. i i

Fig. 9' is a sectional plan view of the parts Fig. 4.

horizontal section on line 7-? cross section on line Fig. 10 is a sectional 10-l0 of Fig. 4, looking downwardly and forwardly. I Fig. 11 is a detail elevation of one of tie element associated therewith.

Fig. 12 is an elevation, represented as. viewed from the rear of the machinejtheshowing the base and driv-fl gears shown in Fig. 10, and of aclutcli right 01. Fig. 4),,showing a.detail. 'of;m echa{ DISm. v Figs. 13 and 14 are elevations, re'spe" tive'ly, of a manually and an automaticall fl operated controller forthe tripping mecha nism. v

f Figs. 15'and ltiiare diagrams illustrating iio the speciel'mode of action of this machine,

and pointing outthe difierence thereof from i that of the machine shown ic ny prior pat- 'ent.

Figs/17 eiid 18 are, diagrams similar to Fig. 15 showing the action of the machine in rinclinggears of different to'oth angles.

the principle of thednvention in advance of a description of the details offthe machine here shown; l6nreprese ts the teeth of an 'involute gear of; stendzird. character I, in meshwiththe eonjugate base racki The K T 15 pitch lines ot-the gear and'ofjthe raclgthe base-line 05f thetooth curves :iriol; the liiie of actio betweeh the'geer'emi showii onw'the" diegram end. are 'clesigtia-teci by appropriate legends; If ine gear grinding maohineg'a grindin Wheel isprowicled withtgi'plene operating: ace haying the some relation to thege arthat; one face of'thelieseggi,

.geerjtooth in grinding teeth of diflerent zmglee; lpii Fig. l5 thetooth angle is the same reck' hasflend the same; relative movement of dis1$leceiiie1 t=:--is j produced between the gear" and-the grinding wheelas occurs when thegeariis'rolled Limes}: with the rock, the

t grinding!Wheehdnreducing the' geertooth to finished: form, willevidentlv generate the c( rret i mol-ute 1 rcuryeithereon This is the principle-uponwhich the machine "disclosed I: in my prion pateiit evorks; Iii-that machine 1 the grinding" Wheel occupies the position of one 'side of etooth Ofelia-so rae'lryand the gear to beggroimdis rolledabout" its pitch circle on a surface corresponding to. the

pit cl'rgline of the rack, under the'control or tapes. Insi ccessive positions of the gear the tooth bein ground takes relations to the grindingiw ee1=like those shown by the positions C, U and C5 of the grinclin wheel'in Fig. 16. Here the grinding whee I is shown in different positions. asf thoughbe ing shifted in accord with a geer roteting v the different positions "it actually, occupiesebout a fixed axis, forcleemess ofilflustration and to avoid the confusion of crossing mounted a Worm 33 which meshes with the fimiex whe'el 28, end is mounted on, preferebiy integral with, e spicdie This? lines caused by 'showin the' gear tooth in 'o in rolling by a grindin Wheel whichremains in one position.

closeclin said patent bylsecurirx" "it'toe oylunder the control of fl'e'xible tapes; and in order to grind gears of different diameters of-pitch circle, it is; necessary to provide for-- eachgdiameter of" ear especial .cylinderof which the surface as the necesseryreletion *to' thenitclicircle of-th gears;

1 Theseme result of: generating li 'pro per *erating element which is fixed esto its p.0si-.

curve as i "drawers; enj a. scribing-point is track teeth;v are 'fhe desirefi motioii {of the gear is produced in the machine dis messes point "at or near the end of e recktooth having a baseengie of zero'degrees; the em "act location of this generating elementheing the intersection of the tooth face with the lineof action. I hevecliscoveretl that by arranging c grimii ig wheelwith its cutting face to'corresp'ond w th a rack tooth face of Zero degrees, and by providing suitable mechanismfor rotetingthe geerlon its axis at any d'esiredz;rete, at the some time that the gear is shifted bodily past the grinding wheei, 1 may by simple adjustments fit the same machine to grind gears of'eny (lie-n1- eter any pitch, enderiy tooth angle, Within limits. This is the principle upon which my present invention is hesechshd its effect is illustrated. ii Figs. 15, 1'}, and. 18, wherein (13,0 C represent the relations of the greater and iii Fig. 18 is less.

Referring now to the illustrated einhodiiew principles, 21 represents the hose or edestel. on, which is'moimted an upright area 22 carrying the bed of the machine and equipped'v vith guidevwirysQQand 245cm I l l "which is mounted the wcrlcholdirig carriage 215, the letter being provided'with the usual iipsembrecing the'guieeweys, as showiiin F1 5 i the gear 2715c be ground. is detechebly coiiveiiie ieefi of description on index Wheel, the ietterhemg heid in piece by a In: the carriage 25 is rotetably mounted a spindle 26, on one end of which i {grinding wheel to successive positions enthe *meiit of the invention which contains the key wood a. nut 80, end covered by a do teehehiecesing 81 "which else includes a Worm box 32. In this Worm box there is one (the leithcnd) encl is fitted in e hush ing 35 fixed one end of the worm box.

The opposite ezid'ofseicl spiiiclle is reduced in diameter jet 3% and has its bearing in e bushing 36 mounted in a forimrdiy projectiiig rite 37 of the bed from 22. The bushy ingf36 is threaded into its supporting socket, and is thereby mode adjustable fork); .puga ,posepresently deserihecl. f

. The grinding ivheelisshow e93 aiid 'is mountetiupoii a huh '39"tc"which ti" 7 clampedbye piete 4: 3; thehiih'isisev cufreduponre spindle 4:1 towhichi sec'ureo e o'piilley I adapted to "receive i xfiri 'mg 'be'lt pass ng owned a pulley ve2 1 o substantially to-the tip of the raviitoeth.

If the eonteet of the grinding wheel with the work were limited in this nmnner, 110w ever, the wear upon the Wheel would be ex;

- eessive, and therefore provision ie. made for sh ftingthe Wheel toward and away from the hue of travel of the worhto distribute the wear In this machine, which axis is nearest to said line oftrevel' when is arranged so that the poiht or outer ex; tremity of the geer tooth is the p -g hi h fipst engages the grindingwheel; the Wheel the grinding-commences, an d it is grit-dually withdrawn so that the point p11, its face which makes Contact with the geek tooth gradually. approeehes its tip; mid then, at

"the eonelusion of the grindingtravel, it is quickly withdrewt to deem the gear and; pei-mit indexingbi": the lattel. Jio' permit of this moveinentthe, Wheelepindle lfis mounted hi a roekiiig Wheel carrier on, the shaft 52;previopsly described. This" arm Sglalso has aprojeetlon 86 eerrying'e which has; ewhub portion'79 mouhted one shaft 80. the 'ends of whiehlmve hearings fixed uponthis'sheftcer ries en e-ntifrictien roll Mwvhmhhearsen eezunSh mounted antifrietionmell 87 whielrhearsfegztinet an edjusteb1eeb1itment 88 on the Wheel eerrie'r; said ehutmentjbehig adjustable for a purpose later described; and being held against the roll 87 'by gravity acting through. it weight 89 on the'ea'rriei' Cam is rotated iirthe direction of the ztr'row shown in Fig. Its surface from the point a to the point pushes out gradually inpin the axis,'end while this portion eats; the- Wheel is greduelly moved outwetd. -From Z) to 0 is a sharp rise, which quickly avithdraws the wheel from the tooth space toper-L mitindexing From '0 to d is a dwell which holds the Wheel away from the gee hile." the. letter isi bei'ng indexed, end'froiri- '(lto. a, is aquielt'fdescent to the lowest point of" the hem for-returning the wheel int-e posit on to commence anew grmdm act on.

lndeatiwg mec7zcme'sm.-As he 'oi'e explained, then genereting motion of the gem. o'tetion. of thewoim 33 While the eerriege is shifted in one direction. "If 'it should be desired that the geeriend ink} is obtainedhjn deli wheel have the smilerolling 'contii-et durin the quiek retum travel "as duringtie slower"woi'king 'trevel, it would be necessary t0 reverse-ythe du'eetion. oi

eyeguhxted length of time eeteig hi hi or at different proportional speed during:

the Whole or a part of the retum'trevel, the? relation of the work to the grindih 'wheel' ifi'er nv t, t l

wohld heso alteredas to hrinfgfle tooth IIItQ-POSifiQIIutO BB ground; It haye here shewn the application to. practiealiuse of that form of the principle qabove' cle- "scribed whieh eonsists ie eeusin the worm to] stand Sillilln, the eourseoft e 'eai'riegep returnihorder to index the work, although without limiting the scope of protectionwhich Ie1aim he; in to that form .aloneor I fexeludmg thereiliom' either of 'theothei'l forms suggested. H In applying theepartie? f q I have made the intermediate'g'em s, 68 eQndfiQ uler form of means chosen for illustration;

in two parts, as before deseribed end'ceuse one of these parts t0 remain stet iohe 'ydufing part of the ca-i riage return. The hub 90 of the gear element 69.(Fig. 10) turns .on a tubular stud 91 which passes thrbugh theholdefii'l 1 and is secured thereto by a and stud 91, and in whieh, is fixed, "by a. V

nut 96, a push rod 97 which thus through the tubular stud 91 andthfough mop ing 98in the adjacent rib ,3? ofthehed 7 frame. On its endit has a head 99. between vhieh me the stud -91 is confined a; spring 100 which holds the geaiflelements infthe relation shown. in the drawings, in" which e eiuteh element .101 on the gear' element For disengaging theeluteh there ispi o- .QO'and to the outer end of whieh s secured a plate 9:? covering theendzoftthehuh 90,

in. condition-to engage and meet with a clutch element 102 on the gear ,Q- end 12) which, on each revolution ofthe' sheftmdispleces ,endwise a connecting rod t 3.04s, pivoted et its upper; end to a iateml 'lower end heingleenfihed by: at guide 107 (Fig 12). This reek shaft eziriies en'ei ml. "108. extending across the end. of the push rod 97; the Whole errangementjheing such arm 105011 a rookfslmft 106' its thatwhen shid tappetpu'ehes on the fed 10,4;

f the iod97 is pushed koutwardandtheagear,1 I

GSunelutthd from. thegeex w. This ac-' tion oceurs' eftenthe werkpeerriage has i ended its working ti'ei elf. end' before. it hes} completed its "zeti i'ntravel. Thejpowei i tifansmiseionfbetweeethefeed serew e-nd-the worm beingfthus disconnected, the-worm stands" still and the index Orm WheeIQZS in telling fever it is turned"throilgh e, o

12 ti'evel, end-s indexes the gear., To make 811131119?" ahgle; than during the feeding [is e of thee-hovedeserihed method of index durin'hj the grinding action on [one tooth-fat" enough @Ouiitlijt thegeee thifeug intense tion. to" the angle through w ich the ear is turned simply by the rolling of the ndex wheel on the worm. That is, the ad- ,ditional' angle of degrees, previously Qdefined, must'be equal to or greater than the angle between corresponding oints on -two adjacent teeth of'the gear. t is also it eel te'or greater han h oo pe es in 93 the teeth in the change gear 70 on the worm to. the number of teeth in the ear 27 being be equal to the ratio o the intermee in ex gear 28 and thev gear 27 have the are different, the desired efi'ect'maybese i cuzfed by compounding the elements 68, 69, tithe i t rm te s repor o to '1' t e ratio of such pitches. That i if the pitch of the index-gear 28 he assumed to be and that of the gear bein ground is p, t en the ratio of theinterme iate gear eleexit 68 to the gear element 69 1s made equal to the ratio of P to 32. Another- '2 5 yr neans of accomplishing the same result 1s to introduce in the train of gears between 67 and 70 another pair of gears having the same ratio. p p p ff'llhe clutch members 101 and 102 are here snows as each being the half ofa ring, the ends of one abutting'against the ends of t e other when engaged, and one ridin'g over g ,-.the other when disengaged. The spring 100 .j automatically restores them into engagea5 meat when the, gear; 68 has completed one rev glntion after disenga ementQ The posior form, or both, oi the tappet 103 de- Lteimines thetime of disengagement of the clutch, to the end-phat the part of the return travel of't'h carriage during which the worni remains stationary will be enough r-to causegcorrectindexing'ofthe work. It '18 .to be understood, of course, that the clutch 'menibers may be. appropriately modified to 4.5 accomplish the desired result of indexing thework incases, where the rotationof the worm in turning thework through a tooth space'is accomplished with less than a cord plete reyolntionpf thefintermediate gear. Tripping m Q'Z anismr-The driife forthe carriage feed mechanism includes a speed reduction gear between the pulley 17 and the shait48. The-pulley turns loosely upon a hub 1080 8) which in turn is rota- :65 table about the ShaftJLS and is provided Iwitha flange 109.. Thepulley carries double planet gears 110,111, which run in mesh with; sun gears 1.12, 113,, respectively, the former of which is fixed to the hub 1080 fifl and the latter to the shaft 48. vWhen the ;fian'ge 109. is held stationary, the planet gears, cause the sun gear 113 .to rotate ber .of beet which may be greater or less,

is than nmsunaar 1 2, hus .innnsahefi 8 slowly sincej' the latter has a different num cessary that the ratio of the number of atecar 68 to the index gear 28, when same pitche" When the pitches of these gears 120.

slowly. When the iiange is no. longer held from rotation, the rotation of the shaft4-8 of course ceases. The purpose of the tripping mechanism about to be described is to release the flange 109 to, stop the machine when all the teeth of a gear have been ground; This tripping mechanism is shown in Figs. 2, 4, 8, 13, and 1 1. A pawl 114 (Fig. 2) is pivoted in position to engage an abutment 115 on the flange 109, and to .it

is connected an arm 116 to'which is pivoted a link 117 connecting said arm with a pivoted rock lever 118 having an arm 119 which bears on the rim of a trip disk or cam This trip cam is fixed to a shaft 121 on which there is also fixed a ratchet wheel 122, (Figs. 4 and 14:) and the latter is driven intermittently by a pawl 123 on a pawl carrier 124 which is oscillated by a connectin rod 125 from an eccentric 126 on the shai t .52. The trip disk 120 has a notch, 127, ,which, when it comes opposite to the .arm

119 allows the latter to enter and permits the pawl 114 to release the flange 109. The pawl is impelled to this effect bya spring In order to start lever 131 carrying a pawl 132 engaging the ratchet 12 2,'andhaving a lug-133 overhanging a fixed"stop."134. When the lever is turned ,freinathe'position shown in Fig. 13 until this 'lug'strikes the stop, it turns the trip disk i120 far enough to crowd the arm 119 out of the notch 127 and shift'the pawl 114: into the notch 115 of the trip flange. A

special ratchet 122 is provided for each size of gear to be. ground, the number of teeth on the ratchet being enough greater than the number of teeth on the gear to permit the above described starting motion.

Adjustment of carriage on bed.-Various adjustments are provided for convenience :One 15 for moving the carand accuracy. riage on the bed without disturbing the screw and its operating mechanism, used the gear, teeth, the gear must be rotated 128 coiled around the link 117 and confined 7 between a collar 129 on said linkand a [guide 130'fixed to the machine base through "which said link passes. the machine again there is provided a hand after adjustment the set screw is again tightslightly toward the grinding whcel.. This is accomplishedby moving the worm 33 endwis and t s fa this ru p sethet t e bushingBG is threaded into its socket as previo isly described; One end of the bushing ulliuts age-111st the shoulder 138 011 the worm spindle, and its other end abuts against a r ivaslier139c fixeclon the same spindle by a wlienf rotated it causes the bushing to be l he onetlirection orthe other.

shifted by means of its threuId-emlwise in v Adjustment of grinding wheel for your diameter aml f? tmz' ngk 'he position of the Wheel and oi its are of swing must be shifted tosuit of different diameters, and 017 this purpose the rocking cairiier 78 is movable about the shaft SOindependently of the operating Min 83, and the abutment 88 which transmits the thrust ofthe ope'iet j of the carrier is nede eciiusteble.

This abutmenthes theforin ofsspiml cam llXGLl OH a shaft 344 having proper heerings inthe Wheel carrier, and also fixed oi thesetitoe'shaft is o gear 145- iii x iesh with a pinionl' 1 16" earifieii 1y a. shaft 14 having "bearings in the wheel carrier and adapted to he turned by a wrench.

. holder. 149 held in s socket 150 on a bracket-- A 151 projecting frointhe base iiesicie "the outer rim of the grinder wheel. The flbllt- 35 the rim of the grinder is ceuseol to oscillate back and forth past-the diamond, and the ment 88 may be adjusted to a point where iatteemay'eiso be mljustecl by shifting the holder 149 in the socket 150 so as to engage the Wheel even. when the letter is in e for ward adj ustment;

- Adjustment of extent of wheel tweet- The depth of teeth varies in gears'of different sizes emi pitches. It is therefoi'e neces sary to vary thefamphtude of swing of the wheel earriei and this is accomplished by giving the'cem 85 a tapered form and mahingit exieily adjustable. The throw of the oem at its small end. is sufiicient for gears of the finest pitch which it is desired to grind,

and the throw at the. large end'is sniiicient for gears of thelezgest piteh, While the-sot feca hetween such ends a continuous gradual taper, Differeptiionee which have respective-1ydifiei ent extents of throw are broughtinto ectionupon the carrier: by.

shifting the can}; end'wise, and therefore the cam isiitted toslide m the shaft 52; It is sthroughslots 153 in the opposite sides o'f-the eogegec'ttherewith by e screw-$11352 pro; videtl'v with en'textensionwhich passes fshefit which is bored out from one end to f "if: the'bore ofthesheft. i. This out has l'1BQ1 fO 1fm0ffi sleeve-engaged near one ei d example, sn -englefof "20; curve may be; varieol by c the flexibility of adji e'tgoe I Iferds. The machine possesses elsotheifun demental essential of aeci rejcy. To secure correct results itis sufiicient 1110 give the w this-point, axial through a nut-flfet-sliclingiy' piop'ert ee to $0 M?" 6 lt nde 't i l ke Wo m wear.The operating face of the wheel gradually become worn ewey by the work and by action of the truing tool, andit must be'wshifted 'endwise totomperisate for this weer. For this pufpose the bearingfbushjug-S157, 158 for the gri'riderfspii'idle 41m hji mounted in a sleeve l59fsli iaLb1eTth -oi1g tubular pert IGOinthe wheel cerrieri" This sleeve is provided i'vitli a tapped which is threaded escrew 1,62 h ai in'ge beenii lug 163 on thetcarrlei' end pro vicled withcollei's embiacmg seidfh g 163,

gZes.-The' pitch or lead of-the screw 6% e f oft inwlute, tooth curves which willf'mesh 1 with at ruck having at giveii tootheiigle, for The toot H n gle "f e'rotavei'tothst of t tional speed of the Worm the screw, which changes t ferent base circle. H Illustrations of si cli Vii: iiations are shown in Figs. 17 endjlSfm eompar'ison with Fig. 15; Fig].l'17shpwingieo the effect of rolling on i'elativelysiiieller base circle,- wlth increase in the angular travel of the teeth end 18 shovi ihg the eii'ect of rolling on e'i'eletiyely l rge; base circle with e smeller angle of movement ofthe teeth.

One means of I 15 to change the gea rslifi'l" and 0; [Aiibther meansis to provide for the gear elements 68 and 69 gears having different numbers '110 of teeth jthe ratio between the iiuimbers of teeth on these gears being equaltothe ratio Q of the cosine oi. thefdesire'clftoothengleie" the cosine of 209, or any other precletev mined angle with respectto Whicir'the screw 1 15 by the machine. mey be'fittcd to produce v Workof arying characteristics, simply and quickly. The provisionjof a i index gear wheel and a! worm for driyil g "the [seine is a particularly useful featuif'efon Iztccou'nt of 33, to provide t gensmissioiiygearsgin lin I ate, of j'rota -95 tionof the gear and. has the same effect. as though thegear were caused to roll on a (1115-;

ticcoiiiplishin ftliisiesiflt diameter of the index gear 28.

.clud'ing the changeable gears, of proper value, all of which are determinable by mathematical calculation according to well understood principles of gearing. It is preferable, however, to give the screw and the worm equal leads, or at least not to have any variance 'further than that occasioned by giving the Worm a multiple thread, the latter being convenient for grinding small gears to avoid an inconveniently large ratio of the change gears.

The simplest form of the problem involved in the use of the machine is the grinding of a gear having the same pitch as the index wheel. In this case the diameter of the change gear on the worm is the same as the diameter of the gear to be ground, and the sum of the diameters of the change gears 67 and '70 is equal to the F romthis condition-variations may be made by chang ing the ratio of the change gears, or the ratio of the intermediate gears, or by introducing a separate pair of connected gears in the gear train, although practically all variations obtainable. by the third named adjustment are obtainable equally by chang- .ing the ratio of the intermediate gears. By

these simple adjustments, together with the corresponding adjustments of the grind- 111g wheel, the machine may be caused to turn out finished accurately formed gears ot any character, any pitch and any tooth.

angle.

The principles embodied in the machine hereinbcfore described are not restricted to one in which the grinding wheel remains in thesame location and the gear is carried in a straight path and. rotated aboutits own axis. It is only necessary that a relative motion should take place between the gear and grinding wheel which is similar to -that occurring between a gear and a rack when running in mesh, whether the rack is stationary and the rocked about it. Means for securing this relative movement 1n all of the ways in or the gear is stationary and the rack is.

which it may occur are within the scope of my invention; 'l-hercforc I do not limit my protection to the specific construction and arrangement he'rc shown except as may be required by the express terms of the claims ereto annexed.

Other features of the invention, includ ing the provision for a lateral or transversemovement of the grinding wheel durmgthe continuance of the grinding action, and the character of means for turning the gear during this action, are not necessarily re-.

stricted to an. arrangement in which the corresponds to the of zero degrees. The transverse movement though still transverse to such line.

, ting tool.

gear rollsover it, or 1 y l o the gear ]S rotated and the rack is moved,

of the wheel is particularly intended to distribute the effect of wear over its face, and is further provided to increase the range of action in grinding teeth of large angle, as indicated in Fig. 17. These results are equally useful in cases where the face of rection of shifting is otherwise than perpendicular to the line 'of relative translative motion between-the grinder and gear, illc cordingly my claims to the last named features are not restricted, except as it appears from their terms, .to the application of such features tothe particular'machine and in the particular form and arrangement hereinbefore described in detail.

It will have become apparent from th foregoing description that a machine embodymg the principles ofmy invention as described accomplishes the important effect of generating correct involute tooth curves by true mathematical generation, as distinanished from reproducing curves previously formed in guides or templets, or in the cut- The term generating is here used with the mathematical definition, and as applied to the specific case described, it means the development of an original curve by the relative motion between the work piece and the cutting point in accordance with the mathematical law of involute curves. As-such motions are simple, consisting only of circular rotation about an axis and linear travel upon straight guides, at rates of speed which are determinable mathematically and are capable of being produced accurately, the result is the generation'in the tooth of an origin a1 curve without sensible error.

grinding wheel is located. Therefrom it ,re-. suits that the axis of the grinding wheel may be set parallel to the line of'relative linear displacement between the work and tool, which insures the greatest possible accuracy in construction and operation of the machine. i,

A grinding wheel is essentially a'cutter, differing from a metallic edged rotary cutting tool in that the cutting points are irregularly scattered over its surfaces insteadof being in given l'ines. of cutter, as for instance those-made of metal having distinct cutting edges in a plane perpendicular to the rotational axis, may be used with like effect in generating and cuttingtooth curves in work pieces whereof the degree of hardness is such as to permit of being cut by such edges; and such cutters are equivalent to the grinding wheel particuv larly herein described within the scope of the grinding wheel is inclined, and the di- Other types ed to rotate and having-its -activeface'in aplaneat right angles to its axis ofrotation a holder forthe gear to bl ground arranged to hold: such gear with the faceof a tooth thereof in contact with said grinding wheel:

face ancl with the base circle f-the gear' [tangent to. a line: parallel tolsaid axis passing through said wheel:face,"andmeansfor" rotating such' gear atthe same: time ats'uch 1 0. AYgear grinding and generating machine comprising a= grinding wheel 'monnted to rotate andihavmg its active face in a plane at rightanglesi to its axis of rotation5i a holder for the gear tobe; ground arrange to liold s11'ch g'ear with the face iota-tooth 1 worm at the -same time to Gmredtiori. v a l a thereo'f in contact with said grinding wheel face, and with the base circleofthe gear tangent to a line parallel. to 'sa1d.ax1s; pass ing through said wheel face',"a toothed ii1-.

dex wheel connected to" the gear to be ground, a driving gear element in -mesh. with said index ,wheel, and means for causingrelative motion toctake place .betweni said gear element and index; wheel atthe velocity: and in the direction which causes as'e circle rolling on said 13. Ina gear grinding and generating machine having algrinding wheel-and, acar ria e ,for' the gear 1*t0 beground mounted I an 4 guided to'travel in a -straightl1ine, a

means forfpi'opelling said carriage backand' f rth1.i s1 1chline "comprising a-rleadlscrewi. engaged-with the carr1age, a pinionon saidf lead a operatively engaging said-segment posite directions.

the gear tobe generated, aleadllscrew enscrew, a gear segment geared tot-said pinion and operable wto rotate theisam eg and In a gear generatingimachinehaving j a rotatable.cuttingtooland a carriage for gaged with 'the'carriage for prope lligig the i same, a' pinion on said screw a-m'segment, V

geared to" said; pinion- ;for rotating tl ielsanie and mounted to rock, and two camsengagin different parts of said segments, oneoff-sai camsarranged and opera mentm one direction, and the othertorock it in the opposite direction.

a" le to rock the seg- A 15. In a gear generating n1achine,.a rotary cutting tool, t a carriage movable 5 past said tool holding'the gearto be cnt,-. means for rotating sald gear while-passingthetool,a

same with its acting portloniiarranged to fcut a side of a tooth onthegeaiyand means the, gear being ground to roll relatively to thehgrindin wheel. face inthe same manner as it woul roll mesh, with a ,ra'ck'of' be ground, a toothedindex wheel monntecl on said "holder in. sif1cl'iim:: ner to tnrn such gear when rotated, fand being of diffor movin holder for the cutting toolmsupporting the line in whichthe carriage moves and to the:

.16. In a gear grindi ng machine, a holder forthe gearto be ground a grinding wheel,

I a holdrfor saidgrindlng wheel, one "013 said holders'being movable withn respect' to the other to prodnce' relative movement be ferent pitch diameter than thegea'r; a grinding Wheel mounted rotatabl-y in {posit on to 1 have its active face make contact 'withthe; face he tooth i: of such -geaqm a worm .in meshwith 'sai'df index*wheeL-means for{ producing relative movement of 'displa'ce- 1 ment between. said holder on-the "one "hand and'saidagr nding ,wheel andqwormonflthe I 4 v for the gear to be ground,'-a grinding, wheel .1

other'{ hand, whereb the; index wheelland gear arerotated, an means wheel and. gear; through a; an additional th p p eset' r h-- i l2. gear 'grindin and generating ine means r ePP t gronnd, .and bein r tthe: grindmv ri'age, mechanism for g ving rotative x mov directionsgto move" the carriage back and:

- forthih s i1f'ch line, and mea-ns f rotatin -grindingwheel' -in a Straight line,- a earriage ducing-a furt' "tcothin contact with f ac -faiidjof the pitch sniffapeof the gear. '1

ously rotatin 1 tween the grinding wheel and gear, with 'the'face of'the former in engagemnt with, "a tooth'of. the-latter, means forsimultanef" v the ear, and means forpro-Tj er re ative movementabetween g the gear and grinding wheel, transverseltoj the pitch surfaceof thegear and ,to the line of the first nained relative movement and I .-'during the continnations of th same; 17. In a geargrinding machine at m having its active face; in a plane, perpen Qdicnlar'to its axis of rotation a. holder for or producing? relative translative movement paralleb t su chl axis ibetwen the grinding wheel -andthe said grinding wheel, means,

gear to he ground means for -.'si1nultane:

to-pr'o a e the new -of.; rolh placing. the wheelttran's versely*"hoth of the .18; In a; gear -g having Idir'ectgonplfthe aforesgnd relative movementjf l. hiring;thecontmnance 1 of such. movement 75 for-rocking thesamecalternately and. in cp -1" the tool transversely both tothe movable. past said wheel and holding the ear to be ground, and meansfor rotating said gear while passing the wheel; a holder for the grinding wheel holding the same i with its acting face in a plane at right angles to theli'ne of travel 'of the carriage, and g tosaid gear-of a scribing point in a plane means for movingthe wheel transversely of said line while in engagement with a tooth ofthe'geanf 19'. in a gear grinding and generating machine having a movable gear'holdin'g carriage,a grinding ,wheel located to engage a tooth of the gear'carried by said carriage Jib " carriagefandpositive said. gear about its 8115 during movement.

; lative, movement base circle rollstangent to a line parallel. 9* -20:

7 ing and having its acting face in-a plane at right angles to the line of movement ofthe means for rotating of the carriage at a'velocity such thatl its to such movement. I

'202 Ina gear grinding machine, a grindwheel, a holder for the same, a gear hold1 means for producing relative transbetween' said 1 gear holderholder,*the grinding and "grinding wheel I wheel'having its acting {face at r ght angles to the direction of such relativefmovement,

arranged toactfupon the side of a tooth of;

the gear'so carriecl,"and means. for rotating thegear'on the carnage while such relative movement takes placeat such a ratethat the linear velocityof the base circle of the gear gearment thereof, i i-grinding wheel located to volut'e curve in the ace of the is equal to't he velocity of such movement.

21. A grinding machine for generating gearftoothcurves, comprising means for holding a gear'bla'nk, agrinding wheel having its acting face perpendicular,

and-its axis parallel, t'o' -a' line tangent to the base- C circle of the gear, and means for producing 0 a combinationtof 'relative'ti'ans lat ve .movements between the gear and grinding-wheel m, rotational "movement of 1 thegear with the effect of rolling the gear on itshbase circle on such tangentline, thereby ca isingthe grinding ,wheel to? 'eneratean oigiginal in-i I ear tootha.

' '22. In a'gear grinding an "generating,

ma hine having a; translatively movable folding carriage and means for rotat ing 'said'gear dnjthe carnage during moveen'gage' a tooth of the gear being thus trans l-ated ai'1d rotatedfandlmeans. tor moving said grinding wheeljtransvers'elg tothe line of travel of the carriagewhile in'engagementj'with such] tooth irsunison with said movement, whereby to distribute the wear eter.

on saidwheel over its actingface. 1

23.,1Amach"ne5as' set" forth i laim 22 distinguished further by means for'-shifting' the location, of the path inwhich the aforesaid movement of the .Wheel' takes place, to coact w'th gears vof larger or smaller diam- :1 2&1; via 3 and generati to swing the same and forth, and

a portion of saidar m, a gearassociated said cam; a ,plnlonf'ln mesh with -"sa1d ge 1;,,, and means for rotating sa1dp1'n1on, whereby issaese rolling the sarlie ing face which,in the rotation of said wheel,

successively occupy the relation with respect surface on which said base circle rolls, and

I means for. so displacing the grinding whe eifi While in contact with a teeth of the gear asw to shift the location of such scribing pointtoward and away from the center of the wheel and thereby distribute the wear of the wheel.

25'. In a grinding machme a gr1ndmg.. 8

wheel, an'oscillative holder for said grinding. wheel, anarm'arrangedto actuate said holder for causing the sameto be oscillated,

a cam arranged to operatesaid arm whereby the holder back and means for altering the angle b tween the holder and the linefromits asap to the cam, whereby to shift the location and limits of the wheel swings. n

are through which the 26. Inna grinding. machine a 1' grinding wheel, aback and forth movabl holder. for. H saidvwheel, an actuator for said older bear ingagainst the same-and movableback and forth for operating it,and an abutment'on said holder," against which said actuator bears,

actuator, I path of movement of the grinding wheelr the-abutment being; adjustable to I i change the relation'between the holder and, I and thereby the location of the 27. In a'grinding machine,- a grinding y wheel, an oscillative holder-for said wheel, an operating arm coaxially mounted with said holder, means for, vibrating said arm, I 1,

and an abutment carried by the holder,

against which said arm bears, said. abutment being adjustable to alter the holder and arm.

t 'an bs w e f 28. In .a grinding. machine,

wheel, an 'oscillative holder for said wheel,

an operatmg arm and wheel, means for v1brat1ng said arm, a

for oscillating saidholder cam movably mountedon said holder having a surface 'abutting'against said arm, difli'erent points in said cam surface bein ,at dif-{ between said grinding wheel holder, and

arm.

w'heel, an oscillative holder carrying said wheel, an operating arm mounted coaxially withsaid holder, means for vibrating said am, acam rotatablymounted on said holder if having'its'cam surface arranged to bear on" to turn the gear and-cam, and therefore grinding achine, a grinding f A ferent distances from the line in w ichthe" adj ust the 'latter to alterthemnglebetween said-holder and arm. n

304 In a gear grinding and generating ma:

chine, a'c-arria ge' 'for the gear toifbengr'ound, an index wheel rotatably' mounted on said M carriage, and with which such gear is rigidly connected, a grinding wheel'past' which the gear is'carried by'movements of the car ri'age,-means for moving said carriage :backand forth, a worm Y meshing with said index wheel',-. means for driving said worm rotatablywhile the carriage is inm'otion in one direction andmeans for-interrupting the "wormdrivewhile the carriage moves in; the 1'5 rcausedito'remain stationary and to turn the oppositeidirection'; -whereby' said worm is indexwheel and therebyindex, the gear.

31. In 7 a; gear-"grinding and'generatin machine 'a holder or :the' ear to be groun a grindingjwheel and a' ho derfor the grinding wheel, means for producingrelative movement between isaid gearf "holder" and grinding wheelin one direction for-grind ing, and in the opposite direction to return the same, mechanism includ ng an indexf wheel associated with the gear and *a driven gear element 'for turning said :index wheel while the grindingpperation' takes place,

and means for causing an interruption in wheel, means for producing relativeimove 'meiitsof displacement between said index i wheel and worm-in opposite directions axially of theworm, wherebythe' index wheel is turned; andme'ans for rotating the wonn at the'same tir'ne' toaturnjtheindex wheel.

through- T an additional angle Ito that given by said relative movement of displacement.

33. In agear grinding machine, a mechag nis'ni forgiving rolling generating move ment to the 'gear to-be;ground,'aiidjfor inde'xing such geaflf m P iaytootheilis dex'wheel-wi h wh h the gear is'cmmected 1a drivingwonm'in-mesh with {said 'index'f wheel, means for producing'relative movements of displacement" betweemsaid lndex wheel and worm m opposite dII'GCtIQIlS'flX ially of the'worm', whereby the index wheel" one" direction. t v 34; In a'gear grindmg -mach1ne,'-a mechafor stopping the rotation of'the'worm 'duris turn ed,'-mea'ns for rotatingthe'worm at the, same time to'turn theindex wheel through, additional-angle to that given by "said yo 'tive movement ofsdis'placement and imea ing ih'e, continuance of such dispidcement in 1f nism' giving s ti "movie wheel,-of a worm meshing with said'wheel, means for producing relative: displacement v 38;:In-a mach" eaccording-to '"composite"gear eompmsing two clutch con t --ncted gean"elements as "part of the-dri r g menttothe 'gear to bd and for indeXing such igear, comprising a I toothed dex wheel with' which the gear'is cornectedp a drlvlng worm 1n mesh withsaid index" wheeh-gneansfor producing-"relative move- -ments dfdisplacement between said'index wheel and worm in opposite directions" axially oftheworm, whereby the- 'index wheel turned, means for rotating the I worm "first in one direction'and-thenfreversely-in unison .with-the opposite displacement:movements,

and meansifor causing the=total--augle =through whic'h the worm is rotated'during the displacement movement in one a direction -to be less than that through "which itis" rotated. in the opposite direction during tha opposite displacement movement. I 35. .In a gear grinding machine, a" mecha-" 'nism for giving rolling generatin move merit to the gear to' be ground, and for indexing such gearycomprising a toothed index wheel with which the gear is connected, 'a driving worm' in mesh with said indek'f wheel, means for producing relative mov'e-; "ments of displacementbetween saidcindex V wheel'and worm in opposite-directions 'ax- 1 ially of the worm, whereby the index wheel is turned, means for-rdtating the worm first j in one direction in unison with the displace? ment movement in one direction, and reversely when the thsplacement movement is reversed, and means for causin the angle of rotation of the worm in one irectionto be less than motion by the amount which causes thegear' its rotation in the opposite di being ground to be turned through the angle between corresponding points on two 1adja- 'cent teeth.

36. The combination witha toothed index movements between said wheel andwornr axially of the latteralternatelyin opposite i directions, whereby the index' wheelg is; turned by rolling in mesh with the worm,

the index wheel through an additional angle? injthe course of the displacement movement in one direction, and means for stopping the rotation of the worm during the displace--- inent movement inthe opposite direction.

37. In combination with anindexwheeL J :a, gear element meshing with said index l 1 wheel, means for producing relativev trans-. r

lative movement between said index 'whe'el and gear-element, whereby the index wheel 110" means for also rotating the worm to "'tnrn is"? rotated, mechanism for independently saidg-translative movement; v

, moving said gear element'tp impart :an addia tionalarotatlon to the index 'gear, and means-1f for interrupting s'uchyzindependent motion" f: the gear :element-' during the existence of j i a 'Iother in order-to stop the rotation of; said worm assetforth;

I B9. In a gear igeneratingjgiindi g chine, a carriage for thegear to be ground,

I fa' grinding -wheel,.means'forfmovingsaid carriage back anj' forthfpast the grindingwheeli-n .a path W ichbrings a tooth of the '10 gear vcarried therebyin operative relation to said wheel, anjindex Iwh'eel rotatably mounted (on said carriage with which the i P gear to be ground is rigidly connected, means;

for giving said index wheel a certain characte'r of rotation duringthe traverse ofthe;

carriageir one direction, whereby. to roll" the gear 'by thegrinding Wheel, ahd rneans for giving a difi'erentcharacter QffrptiltlQll H to the, index wheelyin' the opposite traverse of the carriage to index the gear, T 1,]- I 40, In a machineaccording to claim 39,

a lead screw for moving said carriage faf f worm for rotating said-index wheel, gears,

connected with saidlworm and screw, re

spectively, an interniediatejgear composed of n tWOSQCtlODS one of which mesheswith the" gearjof the' sc'r'ewand'the other with the gear ofthe worm,-said sections being rotatablerelatively/toone another and onebeing; movable axially away. from the other, clutch members'conneoted with said gear sections interengaged when the sections are brought 1 together an d adapted to be disengaged'when -one sectionis moved-away fr'oznthe other," 3 5 and means'for thus, d sengaging said clutch 9 members from time to time diiring the o'per:

" ation 'of the machine: a

V ALIn amachine according to'claim having axially-separable gear sections and r 40 a clutch asset forth, means for separating one of said sections from the othercompris 'ing a rod which is connectedtosaid separable section and is movable endwise, a rotating -shaft, a tappet on said shaft afrock 3 r shaft having two arms, a rod connected to one off a said 1 and extending on said tappet beingarrangedv to be shifted end- "wise-by the: latter, the other arm, of said 5 irockishaft'being arranged to engage the-raid. of said. separable gear section and remove the latter out ofclutched engagement with} the other section. when. said, connectingrod in the oth strained.fro nf'movementwith the carriage," a v itself movable endwise in therhajchine transmission gearingbetween the screw and able" gear-holding carriage adapted tootheduindex W to be g ou .v wo mme 'ggng isfi 11BX75 I Pla f u l e nwJ sEt E o "an; index; wheel with; which, w

pound generating movement: 5 b "gear and the grinding -wheel,1 a

1 the gear to ground is,connec ted, nounted ,rotatablyfonsjaid carriage, 1a. wormme'shing :"withthe teethw of said .indexwheeli and: re,

the forrner, and autom tienieans for period' ieally disconnecting said gearing, whereby chine havinga grinding wheel and a mow R n med-ti wheel for turning the latter 'a sj the carriage inoves,;allead screwmfor moving the carriagev back and forth, that mounted inthe carriage' meshing with said screw; and means for turning Sfl'Id IlIit' I'QlQtlVQlytQ the carriagefor ad usting the carria efand the gear carried thereby, to the grin ing wheel.

in'g wheel, a-toothe'd index wheel connected said carriage back and forth zan1i= t in mesh, with said screw mounted,onethecztrriage in a"rotatable1nanner, a, releasableclain n. a the "carriage normally engaging said .nut L01 iprevent rotation thereof, ,and mefansfass'oea' c-iated avith'SiLidni t for rotating the same" when the clampisrelea'se'd,wherq yftoad- 11151; the carriage and the gear carried thereby w th respect to the grinding wheel.

45. In gear a generating grinding machine,- a carriage; forthe. gear to beground,

:1 -gri nding-.- wheel 'past which said carriage moved,'an index wheelon thebarriage for turning the gear while the carriage "said wheel travels, a worm meshing wit and beingrotatable to give a egnlat'ed rof tation to said ndex ,wheeha d means 'fo'r l'ldjusting g said worm endwis for bringing the tooth of the'gearvto be groundinto a I determined relation with the grinding "a 46.,In a --gearv.generat ng grindmg, -machine, a carriage for the gear to ,bei'ground,

grinding" wheel loca d-with respectto j. said carriage in positi n1 for grinding the faceof. atooth ofsucli g'ear, an index wheel on the carriage connected with v the "gear to a g be gronnd, means Jforjproducing. relative I a 42. In a gear generating grinding ma "55 chine having a? movable carriage-for the.

' gear to"be ground, ascrew for moying'said' carr'age back and forth; means foir'otting f said screw first in one--,direction andflthen movement between said carriage and grindi ing' whee1, a.=wormmeshing with said index r wheel arrangedto rotate said wheeljandth gear while "such relative moyeni t which the wheel has itsbearmg v i -'e g'ed so'as to re ent'iel'a. tive endw1se;movement,,s'ai hil'ig being n frame, and means for moving it so" as t gp Y 1 is atsuch 'times a stopped while th @Wrotatesa Q y I ar fg enerating grinding ma- 9.

e em

4145. 11! a gear*generating grinfing ma-jxv 4 ,chine, 'a grinding wheel, a'l' rioyable gear Q holding carriage' arranged andlf movable tq; 851 carry the gear to lie-ground past said grindj- J adjust the Worm endwise for bringing the tooth of the gear into a given relation with the grinding wheel.-

47.111 a gear generatingi grinding ma chine, a carriage for the gear to be ground,

said carriage in" position for grinding the face of a tooth of such gear, an index wheel Y on the carriage connected with the gear to be ground, means for producing relative movement between said carriage and grinding wheel, a worm meshing with said index wheel arranged to rotate said wheel and the gear while such relative movement takes place in such manner as to produce a 00111- poundgenerating movement between the gear and the grinding wheel, a bushing in 'which the wheel has its bearing and with which it is engaged so asto-prevent rela tive endwise movement, said bushing being in threaded engagement with the machine frame and being rotatable and means for rotating said bushing so as to adjust the same endwise and thereby correspondingly displace the worm to bring the tooth of the gear into a given relation with the grinding wheel.

48. In a gear generating grinding machine, a grinding wheel, a carriage for the gear to, be ground, means for moving said carnage past the grinding wheel, means for rotating the gear at the same time, means for moving the wheel transversely to the line of travel of the gear to its pitch surface during the traverse of the gear, and

i'neans for varying the extent of such travel t bf. the wheel for gears having teeth of diffe'rent dept s. v

49. The combination with a grinding,

wheel carrier movable back and forth, a rotatable cam having a cam surface arranged to actuate said carrier so as to cause the same to move back and'forth, said cam having zones wherein the extent of throw is different from. that in other zones, and means for shifting said cam so as tobring different zones thereof in position to 0p -erate said carrier. 1 a grinding wheel, located with respect to .ment arranged to be actuated by said cam,

the cam being formed with diiierent 'extents of throw in different zones, and means fer eflecting relative adjustments between the cam and said driven element such as to bring different zones of the cam into operative relation with the driven element.

52. The combination with a shaft, a cam -mounted on said shaft with provision for movement axially thereof and having its cam surface zones which diifer from one another in the extent of throw thereof, a

driven element bearing on said cam surface and actuated thereby, said shaft being internally bored and having a slot in its side, a nut adapted to slide in the bore of said shaft, a pin passing from said cam through said slot and engaged with said nut, and a screw threadedinto saidnut and project-- ing. from the bore of said shaft, adapted to be rotated to shift the cam axially, where--- by to bring different zones of the cam into coaction with said driven element.

In testimony whereof I have afiixed my signature.

EDWIN n. narrows. 

